Generators produce electric current through the interaction of a magnet and a coil. When a magnet is moved through a coil, it will change the magnet flux in the coil to induce a voltage in the coil.
U.S. Pat. No. 5,347,186, which issued Sep. 13, 1994 to Konotchick, discloses an electric power generator having two magnets which oppose each other. One magnet is positioned above the other magnet and is attached to a platform. The positioning of the magnets in this fashion causes the first magnet to float above the second magnet. As force is applied to the platform, it and the first magnet pass through coils of wire to produce a magnet flux. An external force is necessary to cause movement of the first magnet. In one embodiment, shaking of the device causes movement of magnets to produce a voltage.
Light emitting diodes can be electrically coupled to a coil. The light emitting diodes emit light responsive to a current generated in the coil. U.S. Pat. No. 4,775,919 which issued Oct. 4, 1988 to Pearsall et al. discloses a wheel cover which has lights around the circumference of a housing within the wheel cover. Coils are mounted about a first housing. A second housing which contains magnets is mounted within the first housing. Current is produced as the magnets are rotated within the first housing. This current energizes the light emitting diodes.
The electric power generators of the prior art generally require high rotational speed for current generation. Such devices are thus unsuitable for use with bicycles or other self-propelled vehicles.
Further, electric power generators of the prior art are not self contained requiring complicated installation procedures.